HI Bill... Yes, the HDBX version goes that high, it was the base BX that I didn't think went past 50 feet.
Tom Holmes, N8ZM Tipp City, OH EM79 > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of WB6BNQ > Sent: Friday, September 03, 2010 9:38 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Freestanding mast > > Tom, > > Actually the Rohn HDBX towers went up to 64 feet (not counting any pipe used to > mount the Beams) free standing as I have one. What happens is the amount of > allowed loading decreases with height. Just sticking up a GPS antenna would not > overload a HDBX at 64 feet. > > You are right about it being a PITA as for climbing. Each section is only 8 feet > in length but narrows as it goes up. It is possible with the right base to have > it in a tilt-over arrangement. Otherwise, it helps to rent a man-lift to do the > assembly if you got the guts to go in one. > > Bill....WB6BNQ > > > Tom Holmes wrote: > > > Charles... > > > > Rohn's HDBX series would go to 50 feet, free-standing. It is a real pain to > > climb because the braces cross in an 'X' pattern, but is quite sturdy. Two > > reasonably fit climbers plus a one person ground crew could put it up in a > > few hours once the base is ready. These towers tend to twist more than rock, > > unlike Rohn 25, 45, or 55. > > > > For your minimal load GPS antenna, even the BX series would be adequate, but > > I don't believe there is a 50 foot version. > > > > Now that I think about it, Rohn sold off all of the various BX series, and > > it is now marketed by Thomas & Shelby. > > > > Any piece of tubing you would try to take to 50 feet would likely buckle > > under its own weight and length pretty quickly (all of you ME's and physics > > majors can correct my terminology and choice of failure modes off list, the > > point being that it WILL fall down if you can even get it put up), and would > > definitely need to be guyed. > > > > This leads me to another possibility, if money is not a concern. One ham > > friend of mine has a 120 foot tower that is based on those tapered lighting > > supports you see along the freeways. It is galvanized and consists of three > > sections that simply nest for about a 10 foot overlap. Of course, it takes a > > crane to assemble. Remember, I said if money is not a concern...but it does > > look very nice and serious and professional. Climbing it is not for the > > faint of heart, believe me! > > > > Tom Holmes, N8ZM > > Tipp City, OH > > EM79 > > > > > -----Original Message----- > > > From: [email protected] [mailto:[email protected]] On > > > Behalf Of Charles P. Steinmetz > > > Sent: Friday, September 03, 2010 1:08 AM > > > To: Discussion of precise time and frequency measurement > > > Subject: Re: [time-nuts] Freestanding mast > > > > > > Stanley wrote: > > > > > > >ROHN 9H50 34 Foot Telescopic TV Wireless Antenna Push Up Mast > > > > > > Interesting suggestion. Rohn is well known to me, though I don't > > > typically think of them for things like push-up masts. > > > > > > For those suggesting 6-10' of pipe, at my rooftop I get a reception > > > cone of about 50 degrees elevation and above during the vegetated > > > months (say, mid-March through mid-November), and about 30 degrees > > > and above in the dead of winter, due mostly to dense tree cover that > > > is 60-80 feet tall. So, I'd really need to get 20 feet + above the > > > chimney (50+ feet above the ground) for a significant > > > improvement. The suburban residential lot size doesn't leave me much > > > to work with (no centrally-located tower, therefore no guys unless I > > > negotiated easements with the neighbors, and Hell will never be that > > > cold...). I doubt I could get a permit for 80' of Rohn 55. Maybe if > > > I put a wind generator on it.... > > > > > > Thanks again, > > > > > > Charles > > > > > > > > > > > > > > > > > > _______________________________________________ > > > time-nuts mailing list -- [email protected] > > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > and follow the instructions there. > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
